The new Hydrangea cultivar is a product of a planned breeding program conducted by the inventor, Jean Renault in Gorron, France. The objective of the breeding program was to produce new Hydrangea paniculata varieties for garden use. The cross pollination resulting in this new variety was made during 2004.
The seed parent is an unnamed, unpatented proprietary variety of Hydrangea paniculata. The pollen parent is a different unnamed, unpatented proprietary variety of Hydrangea paniculata. The new variety was identified as a potentially interesting selection June of 2007, at a commercial nursery in Gorron, France.
Asexual reproduction of the new cultivar ‘RENSAM’ by softwood cuttings was first performed in July of 2007, at commercial greenhouse in Gorron, France. Subsequent propagation has shown that the unique features of this cultivar are stable and reproduced true to type in multiple successive generations.